Global Warming/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby Tim and Moby are standing in front of a house in a snowstorm. Tim is wearing a coat, hat, and gloves while Moby is wearing a hat and scarf. TIM: Brrrr. Sure is cold, even for January. Moby holds up a piece of paper that blows into Tim's face. Tim reads from the typed letter. TIM: Dear Tim and Moby, it's freezing outside! What ever happened to global warming? From, Walter. Hi, Walter. An animation shows a globe that has a face with a thermometer in its mouth. A doctor reads the thermometer and puts dots on a chart showing changes in temperature. Additional dots show the temperature rising. The chart shows the years from 1880 to 2020. The left line reads "Average Global Temperatures," and the bottom line reads "Year." TIM: Global warming is about the average temperature across the entire planet. We've been tracking that number every year for more than a century. Since then, it's climbed by about one-and-a-half degrees Fahrenheit. Moby throws a snowball, hitting Tim in the face. TIM: Blargh. MOBY: Beep. An image shows a frozen thermometer. Animations show a snowstorm and Tim standing on a beach wearing a coat, scarf, and hat. TIM: Ah, no. A warming planet doesn't mean there won't be any cold days. Or that there won't be any more snowstorms. Or even that your town can't have a cooler summer than usual. An image shows twelve monthly calendars. TIM: Those are all examples of weather; what's going on outside in one place, at one particular time. An image shows calendars for the years 1942 through 2004. TIM: Global warming is a change in the world's climate: the pattern of weather over long periods. An image shows an Average Global Temperatures graph. MOBY: Beep. TIM: Each of these yearly temperature readings is an example of weather. They're kind of all over the place. The same image zooms in on two dots on the temperature graph, representing two consecutive years. Images of the sun and a rain cloud appear, representing the extremes in temperature from year to year. TIM: We can't predict if one year will be hotter or colder than the next. The image zooms out and a red line connects the dots on the graph, showing a clear upward trend in overall temperatures through the years. TIM: But the overall trend is unmistakable. That is global warming. MOBY: Beep. TIM: It's caused by certain gases in our atmosphere. The more of these gases there are, the hotter the planet gets. A line is added on the right of the chart that reads "CO2 Concentration (ppm)" and ranges from 270 on the bottom to 390 at the top. MOBY: Beep. An animation of the earth shows pulsating lines and arrows that represent the sun’s rays bouncing off the earth. Then arrows point from the globe to a barrier line around it, representing trapped hot air. TIM: When sunlight hits the earth, land and water soak up some of that energy. A lot more reflects off the surface as heat. An animation shows molecules represented by their colored symbols. A frame around them represents a barrier. TIM: Gases like carbon dioxide and methane act as a barrier. They're really effective at absorbing and redirecting heat. That's why we call them greenhouse gases. An animation of a greenhouse is shown next to the globe with the sunlight animation. TIM: Like a greenhouse, they let sunlight through easily. Then trap the heat that bounces off the surface. This is known as the greenhouse effect. Moby is shown shivering on a gray planet next to a big thermometer. TIM: Without it, our planet would be a cold; lifeless rock. The thermometer rises and the rock island turns into a sunny field. Moby is now comfortable. TIM: Until recently, natural processes keep the level of greenhouse gases just right. MOBY: Beep. Behind Moby are factories blowing out smoke, oil rigs, and a city skyline. TIM: But human activity is throwing off this delicate balance. Our modern world depends on burning fossil fuels. Coal, oil, and gas supply the energy that makes our lives so comfortable and convenient. Tim and Moby are walking in a snowstorm. TIM: But they release huge amounts of carbon dioxide, a powerful greenhouse gas. MOBY: Beep. An image shows Moby in front of the factory, oil rigs, and the city skyline, while rows of cows appear in front of him. Methane gas rises above the cows. TIM: Large-scale food production is another source. We keep billions of cows and other livestock for meat and dairy. Their digestion produces methane. It traps twenty times more heat than carbon dioxide. MOBY: Beep. TIM: The problem isn't only about adding greenhouse gases. An animation shows a forest with trees being cut down. A pop-up shows leaves absorbing harmful particles from the air. Another animation shows a large forest fire. TIM: We're also destroying Earth's ability to remove those gases from the air. Chopping down forests, for example. The average tree absorbs fifty pounds of carbon dioxide each year. As we cut them down, we lose their natural cooling effect. And in many places, forests are cleared through burning. That releases all the stored-up carbon back into the air. MOBY: Beep. TIM: Right, industry and agriculture are amplifying the greenhouse effect. The result is rapid warming. MOBY: Beep. An image shows a man outdoors in the cold, holding a long piece of ice with bubbles in it. TIM: Earth's climate has changed before. We know that from studying air bubbles trapped in ancient ice. An image shows a chart with temperatures ranging from -12 to 8 degrees Celsius in increments of four. The left line is labeled °C difference. A line representing low and high temperature ranges shows the changes in temperature slowly rising. TIM: The ice cores tell us that the temperature continually rises and falls. In other words, earth's climate is constantly changing. MOBY: Beep. TIM: Ah, but there's a difference. The temperature chart is shown again. Numbers are added to the bottom line from eight hundred to zero in increments of one hundred. The bottom line is labeled: Thousands of years ago. TIM: This natural rate of climate change has been slow. A small portion of the same chart is shaded to show "25,000 Years." TIM: A shift of a couple degrees ordinarily takes thousands of years. An animation shows a bunny hopping through different types of climate changes. The heading reads "Thousands of Years" while the number below it changes. The bunny changes along with the climate changes. TIM: That gives organisms time to adapt to changing conditions. One species might move to a milder climate, another could evolve new traits. Man-made warming is moving way too fast for life to keep up with it. At this rate, thousands of species will go extinct by the end of the century. MOBY: Beep. TIM: Yeah, one or two degrees may not seem like much. An animation shows a sick-looking globe in a hospital, hooked up to an IV. A thermometer is in its mouth with the mercury reaching nearly to the top. The thermometer shows that the temperature has changed by two degrees. TIM: But our planet is a fragile living system, just like the human body. Raising temperatures even a couple of degrees could have a huge impact. MOBY: Beep? An animation shows coral growing on the bottom of the ocean. Fish swim above them, then rapidly swim away as the coral reefs lose their color. TIM: Our oceans are currently absorbing most of the additional warmth. This is destroying coral reefs that are home to thousands of species. An animation shows the globe, with white areas representing ice, melting and disappearing. TIM: The polar ice caps are melting, causing sea levels to rise. That'll be an enormous problem for coastal cities. MOBY: Beep. An animation shows snow-capped mountains with water flowing down them into green fields. The snow dissolves, the water flow disappears, and the green fields dry up. TIM: Yep, in many parts of the world, ice is a major part of the water supply. MOBY: Beep. TIM: As mountain glaciers melt, these places will experience more droughts and food shortages. Plus, rising temperatures lead to extreme weather patterns. MOBY: Beep. TIM: Simply put, warmer air has more energy. Animations show a large spinning cloud over water; people and animals on tops of houses and other objects in a flood; a blizzard; and an area of green trees turning into desert. TIM: That means stronger storms and hurricanes. Not to mention heavier rainfall and floods. In some places, it will mean more severe blizzards. In other regions, rainfall will dry up, and forests will turn to desert. That's why many scientists prefer the term global climate change over global warming. Because temperature alone may not be the most noticeable effect. MOBY: Beep! TIM: I know. It's a pretty scary situation. But there are solutions. Images shows a recycle symbol and a light bulb. Animations show a bicyclist and a man showering. TIM: Individually, you can help by conserving energy. Like by walking or biking, instead of getting a ride to places. By using more efficient light bulbs, and switching them off when you leave a room. And even taking shorter showers. Animations show an oil rig and windmills turning. TIM: The most important step is that we move away from fossil fuels. Renewable energies like solar and wind add no carbon to the atmosphere. That's why countries are investing in these technologies like never before. MOBY: Beep. Moby goes off and gets a chalkboard. He draws a diagram of four small space ships shooting lasers at the sun. MOBY: Beep. Beep. TIM: Hey, you know what? The answer to everything isn't lasers. MOBY: Beep. Moby erases the drawing. He draws and points to a sun, its rays, and a large umbrella above the earth. MOBY: Beep. Beep. Beep. Beep. TIM: Uh, all right. Let's hear the laser idea. Category:BrainPOP Transcripts Category:BrainPOP Science Transcripts